Laden with heavy weaponry the AC-130 gunships were ready, the 1st Squadron of the 4th Cavalry was poised for attack and, sitting in front of their computer screens, US intelligence officers were about to record an extraordinary blow-by-blow account of the biggest US offensive since the invasion of Iraq in March 2003.

It was just after midnight on 1 October 2004, 17 months to the day since George Bush had announced the end of US combat operations in Iraq. The city of Samarra, 80 miles north of Baghdad, had become a no-go area for US forces with insurgents ensconced in all the main civic buildings as well as its famous al-Askari mosque.

Of the tens of thousands of battles reported in the Iraq war logs, few compare in their graphic detail to the account of Operation Baton Rouge, the effort to retake Samarra. It encapsulates the harsh reality of asymmetric war – massive firepower against small groups of insurgents in heavily populated streets.

"Kill boxes 1A and 1B closed," says the second entry at 0030, using a blunt term for a set of grid references where US air and ground forces are permitted to shoot anything without further co-ordination with other units, though they are still supposed to get positive identification of targets and minimise collateral damage.

Key objects in Samarra were given American presidents' names. Insurgents were called "anti-Iraqi forces" (AIF).

The time came to enter the mosque. US commanders asked Iraqi troops to conduct this part of the offensive. "At 1215 36th Iraqi battalion entered the Golden mosque on Obj Monroe and began search … 36th reports AK-47s found in the mosque … At 1222 36th commando reports taking small arms fire inside the mosque … At 1226 36th commando reported taking 26 detainees with 25 weapons inside the Golden mosque."

The commandos later entered the town's general hospital and detained 50 people suspected of being insurgents.

The logs contain no reference to any civilian deaths. Nor did US military officials admit to any in their public statements. According to US military officials at the time 127 insurgents were killed, 60 wounded and 128 detained.

But Zidan Khalaf of the Associated Press, one of the few reporters to cover the operation, quoted an official at Samarra general hospital as reporting that 70 bodies had been brought to the morgue. Twenty-three were children and 18 women. There were 23 women among the 160 wounded. The Iraq Body Count gives a total of 48 civilian deaths for the 36-hour battle.